1. Field of the Invention
The present invention relates generally to a pair of viewing glasses and, more particularly, to a pair of viewing glasses for seeing a stereoscopic or three-dimensional image from a two-dimensional image.
2. Description of the Related Art
Viewing glasses for stereoscopic pictures have been used in the past in which a stereoscopic or three-dimensional image is produced by images played back by a two-dimensional image display apparatus, such as a television, motion picture or the like which is viewed through a pair of viewing glasses or spectacles.
To produce a three-dimensional image through the use of the viewing glasses for stereoscopic pictures, it has been proposed that the two lenses of the viewing glasses be polarized, with one of the lenses having a polarizing plane lying at an angle different than the polarizing plane of the other lens, or that the lenses be based on different color systems, such as one lens being a red color filter and the other lens being a blue color filter. Of course, the image being viewed must be presented in the corresponding format.
In addition, U.S. Pat. No. 4,705,371 describes a pair of viewing glasses based on the principle of the Pulfrich effect. In this reference, the viewing glasses are formed on the basis of the Pulfrich effect and have one of the eye lenses of a greater optical density than the other eye lens.
In the use of viewing glasses based on the Pulfrich effect, when an image is viewed through a pair glasses having a dark right-eye lens and a light left-eye lens, an object moving from left to right in an image is viewed as a three-dimensional image. When, on the other hand, a two-dimensional image is viewed through a pair of glasses having a dark left-eye lens and a light right-eye lens, an object moving from right to left in a two-dimensional image is viewed as a three-dimensional image. Accordingly, by utilizing the aforenoted viewer glasses for stereoscopic pictures, it is possible to view a normal two-dimensional image such as a television image, a motion picture image or the like as a stereoscopic image.
When viewer wears the aforementioned viewing glasses for viewing the stereoscopic picture based on the principle of the Pulfrich effect, the viewer must identify which dark or light lens is intended for which eye, otherwise the viewer cannot view the stereoscopic image correctly. Nevertheless, the known viewing glasses for stereoscopic pictures are inconvenient since the position, or orientation, of the glasses is not readily or easily ascertainable.
Furthermore, if the viewer requires vision correcting glasses, such as to correct nearsightedness, the viewer must wear the stereoscopic viewing glasses over the viewer's vision correcting glasses. This is not only true for stereoscopic viewing glasses based on the Pulfrich effect, but also is true for viewing glasses for stereoscopic pictures that are based on other than the Pulfrich effect, such as the polarized system or the two color system glasses as described above.
Accordingly, a pair of viewing glasses for stereoscopic pictures must be made large enough to enable a viewer wearing vision correcting glasses to also wear the stereoscopic viewing glasses. Nevertheless, when a viewer wears the stereoscopic viewing glasses over standard glasses, the stereoscopic viewing glasses are generally not stable and tend to slip down or become misaligned, which is uncomfortable and disadvantageous for the viewer.
Furthermore, for those who do not wear vision correcting glasses, such stereoscopic viewing glasses are generally too large in size to enable the viewer to wear them in a properly fitted fashion.